With most people today communicating via text message, Facebook post or e-mail, the old-fashioned letter has become a curiosity. Handwritten, folded into thirds, penned in the writer’s unique hand, the letter is as much a relic as the phone booth, the typewriter and the telegram. Now we collect letters rather than write them, and occasionally a trove turns up at auction, as did the recent collection of Jackie Kennedy Onassis’s revealing correspondence with an Irish priest.

Therefore I approached “Signed, Sealed, Delivered,” Nina Sankovitch’s celebration of letter writing, with anticipation. Surely, she would have insight into what is almost a lost art. Unfortunately, this random collection of musings never really coalesces.

Initially the book focuses on a trunk of letters discovered in a shed behind Sankovitch’s New York City row house. While these letters fascinate her, the few excerpts she quotes are not that captivating, and the family’s story never seems to go anywhere. Another possible framing device, the letters she writes to her son who is away at college, also falls flat.

It’s curious that in this book about letters, no epistles are reproduced in their entirety, although the form itself could have given the book the structure it lacks. Each chapter purports to have a subject, including advice (“Correspondence Counseling”) and love letters (“Written Under the Cloak” and “To End with Love”). Yet Sankovitch rambles so much that several times I had to check the chapter title to remind myself what, exactly, it was supposed to be about.

All of this is a shame, because with a clearer focus this book could have been compelling. If she had focused on love letters, for example, the author would have had more than enough material and the opportunity to make observations about what is a genre all its own.

When my parents died, we discovered a box of the letters they had sent while my father fought in Europe during World War II. Like all love letters, they were a battle of verb tenses — remembering the past, surviving the present, anticipating the future. In Sankovitch’s book, I was hoping for more insight into how the love letter works.

Her best observations come in the brief consideration she gives to the effect of technology on letter writing. “To be dependent on e-mail and text is to have access to immediate response — but diminishes the rich opportunities that come from living with delayed gratification,” she writes. “For so much happens in the delay.”

Betty J. Cotter teaches at the University of Rhode Island and Three Rivers Community College in Norwich, Conn. She is the author of “The Winters” (2012) and “Roberta’s Woods” (2008).